Anti-coring device for use with bit mounting means on mining, earth working and digging machines

ABSTRACT

An anti-coring device to protect the bit mounting means on a mining machine, digging machine, earth working machine or the like. The anti-coring device comprises a replaceable member detachable affixed at the forward face of the mounting means and configured with respect to the mounting means to be subjected to the wear by cores which would normally be sustained by the mounting means. In certain embodiments, the anti-coring device will be provided with a notch or perforation through which the bit passes, so that support for the anti-coring device can be provided in part at least by the bit.

keler ANTI-CURING DEVICE FOR USE WITH BIT MOUNTING MEANS ON MINING,EARTH WORKING AND DIGGING MACHINES Claude B. Krekeler, Cincinnati, OhioThe Cincinnati Mine Machinery Co., Cincinnati, Ohio Filed: Sept. 20,1971 Appl. No.2 181,771

Related US. Application Data Continuation-in-part of Ser. No. 842,791,June 30, 1969, Pat. No. 3,622,206, which is a continuation-in-part ofSer. No. 753,398, Aug. 19, 1968.

Inventor:

Assignee:

11.8. CI 299/86, 37/142, 299/92 Int. Cl. E21c 35/18 Field of Search299/79-93; 175/413;

37/142 R, 142 A, 141 T References Cited UNITED STATES PATENTS 2/1971Teasdale 37/142 R Dec. 11, 1973 3,659,654 5/1972 Davies et a1. 37/142 R3,550,691 12/1970 Davies et a1 37/142 R UX 3,020,655 2/1962 Launder37/142 R 3,512,838 5/1970 Kniff i 299/92 X 1,414,586 5/1922 Russell299/91 X Primary ExaminerErnest R. Purser Attorney-Melville, Strasser,Foster & Hoffman [57] ABSTRACT An anti-coring device to protect the bitmounting means on a mining machine, digging machine, earth workingmachine or the like. The anti-coring device comprises a replaceablemember detachable affixed at the forward face of the mounting means andconfigured with respect to the mounting means to be subjected to thewear by cores which would normally be sustained by the mounting means.In certain embodiments, the anti-coring device will be provided with anotch or perforation through which the bit passes, so that support forthe anti-coring device can be provided in part at least by the bit.

8 Claims, 15 Drawing Figures PMEmEunmn 191a i 3,778 11 sum 1hr 4 2INVENTO R/S CLAUDE 5. AKEKELE/E J and Win! ATTORNEYS PMENYEDUEQ 1 1 IanSHEET 3 OF fi INVENTORK S CLAUDE 5. min-2;?

BY %awa, L952? and W10)! ATTORNEYS ANTI-CORING DEVICE FOR USE WITH BITMOUNTING MEANS ON MINING, EARTH WORKING AND DIGGING MACHINESCROSS-REFERENCE TO RELATED APPLICATIONS This isa continuation-in-part ofthe copending application of the same inventor, Ser. No. 842,791, filedJune 30, 1969 and entitled, CUTTER BITS AND MEANS FOR MOUNTING THEM (nowU.S. Pat. No. 3,622,206) which, in turn, is a continuation-in-part ofthe copending applcation of the same inventor (now abandoned), Ser. No.753,398, filed Aug. I9, 1968 and entitled CUTTER BITS AND MEANS .FORMOUNT- ING THEM.

BACKGROUND OF THE INVENTION 1. Field of the Invention The presentinvention relates to a protective device for the mounting means ofcutter bits, digger teeth and the like, and more particularly to areadily replaceable means to protect'the mounting means from coring.

2. Description of the Prior Art The anti-coring device of the presentinvention is applicable to a wide variety of mounting means for a widevariety of cutter bits, digger teeth and the like. The problem of coringas will be described hereinafter, is encountered both with the cutterbit-mounting means assemblies of mining machines and the diggertoothmounting means assemblies of digging machines, earth workingmachines and the like. Thus, 'as used herein, the terms bit and mountingmeans are intended to be broadly construed to encompass both cutter bitsand digger teeth and their respective mounting means.

Prior art workers have developed a great many embodiments of bits andmounting means for use with mining machines. In some instances, thebit-mounting means assemblies are so construed as to permit freerotation of the bit in its mounting means. In other instances, the bitsare intended to be non-rotatively held within their mounting means.

In use, the mounting means are affixed to adriven element of'the miningmachine. The driven element may take a number of forms such as a cutterchain, a cutter wheel, a cutter arm or a rotating drum.

Irrespective of the nature of the driven element of the mining machine,the cutter bit-mounting means assemblies are generally arranged thereonin a pattern so that the cut produced thereby in the material beingmined is of sufficient width to accept a portion of the driven elementand thereby permit it to be advanced toward the material being cut. As aconsequence, the above mentioned pattern of arrangement of thebit-mounting means assemblies is such that the cutting tips of the bits,as they advance in the cutting direction, follow parallel or concentricpaths through the material. While the above mentioned patternarrangement is intended to bring these paths as close together as isfeasible, they nevertheless are spaced from each other by a shortdistance. As a consequence, there will be formed between adjacent pathsa core of unfractured material which will tend to grow as the bitsproceed in the cutting direction. Thus, in essence, there will be rowsof unfractured material between the paths followed by the bit cuttingtips.

The formation of cores in the material being mined is substantiallyunavoidable. However, core growth is greater in some types of materialthan in others. For example, material such as relatively clean coal,which is easily fractured, displays a minimum core growth. On the otherhand, the mining of material such as coal containing stratifiedimpurities (including iron pyrites, sulfur, fire clay, etc.), which isdifflcultly fractured, results in serious core growth.

When cores are formed, a portion of them will lie in the path of travelof the mounting means of the bits. While impact with the mounting meanswill fracture the coresand remove them, the mounting means themselvesare subjected to wear by virtue of this contact or impact. Such wear ofthe mounting means, caused by the cores, is generally referred to ascoring. With the passage of time, this wear will finally result in thenecessity for replacing the mounting means.

In the mining means process, bits require frequent replacement andprovision is generally made so that their replacement can be easily andquickly affected. Mounting means, on the other hand, generally have amuch greater service life than the cutter bits and are not intended forfrequent replacement. In general, the mounting means are affixed to thedriven element of the mining machine by welding or the like. Thus, replacement of the mounting means is both difficult'and time consuming. Inaddition, mounting means are not made as expendable items, and thereforeare far more expensive than the bits.

While the problem of coring has plagued the mining industry for manyyears, prior art worker have simply accepted it as an unavoidableproblem. The present invention is based upon the discovery that if asimple, expendable, inexpensive protective means is removably affixed atthe forward face of the mounting means, the protective means will besubjected to the coring or wear normally sustained by the mountingmeans. When the coring of the protective means of the present inventionbecomes severe, it may be easily and quickly replaced. Therefore, theservice life of the more expensive mounting means is greatly increased.

SUMMARY OF THE INVENTION The anti-coring device of the present inventioncomprises a metallic member removably mountable at the forward face of abit mounting means. While the anticoring device may be mounted inanysuitable fashion, one simple arrangement entails the provision of meanson the mounting means to provide a slot on the forward face thereof. Theanti-coring device is provided with a tongue receivable in the slot. Thetongue may be configured to have a frictional engagement in the slot.

In certain embodiments of the present invention, the anti-coring devicehas a perforation therethrough, through which the bit extends. Thus, thebit assures that the tongue of the anti-coring device cannot bedislodged from the mounting means slot.

In other embodiments of the present invention, the bit again extendsthrough a perforation in the anticoring device. In these instanceshowever, the anticoring device also provides an abutment surface adaptedto cooperate with the gauge-determining abutment surface or surfaces onthe bit. Thus, in these embodiments the device not only serves as ananti-coring device, but also as a replaceable gauge-determining abutmentsurface.

In yet another embodiment of the present invention, the anti-coringdevice is provided with a slot, rather than a perforation, through whichthe bit extends.

In another embodiment of the present invention the anti-coring device isheld in place by the bit and a hook-like engagement of the mountingmeans. Finally, the anti-coring device may be held in place by the bitalone, there being means to retain the anti-coring device on the bit.

In all of the embodiments of the present invention the anti-coringdevice does not interfere with replacement of the bits.

As used herein, the term cutting direction refers to the direction inwhich the bit-mounting means assembly is moved by the driven element towhich they are mounted, irrespective of any movement of the entiremachine itself. The term forward surface of the mounting means refers tothat surface substantially facing in the cutting direction and normallysubject to coring.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view,partly in cross section, illustrating an exemplary form of bit-mountingmeans assembly provided with an anti-coring device of the presentinvention.

FIG. 2 is a perspective view of the anti-coring device illustrated inFIG. 1.

FIG. 3 is a front elevational view of the structure of FIG. 1.

FIG. 4 is a side elevational view, partly in cross section, illustratinganother exemplary form of bitmounting means assembly and the applicationof the anti-coring device of the present invention thereto.

FIG. 5 is a side elevational view, partly. in cross section, similar tothat of FIG. 4, but illustrating the use of an anti-coring devicepresenting a gauge-determining surface cooperating with thegauge-determining abutment surface of the bit.

FIG. 6 is a side elevational view, partly in cross section, of anotherform of bit-mounting means assembly with an anti-coring device of thepresent invention applied thereto.

FIG. 7 is a perspective view of the structure of FIG. 6.

FIG. 8 is a side elevational view, partly in cross section, similar tothat of FIG. 6 and illustrating the use of an anti-coring devicepresenting a gauge-determining abutment surface cooperating with thegaugedetermining abutment surfaces of the bit.

FIG. 9 is a side elevational view, partly in cross section, illustratingthe application of the anti-coring device to yet another exemplary formof bit-mounting means assembly.

FIG. 10 is a side elevational view, partly in cross section,illustrating an anti-coring device similar to that of FIG. 8.

FIG. 11 is a perspective view similar to FIG. 7 and illustrates anotherform of anti-coring device of the present invention, similar to that ofFIG. 10.

FIG. 12 is a side elevational view, partly in cross section,illustrating the application of the anti-coring device of the presentinvention to the mounting means of a digger tooth.

FIG. 13 is a view, similar to FIG. 12, illustrating an alternate meansof affixing the anti coring device to the mounting means of a diggertooth.

FIGS. 14 and 15 are side elevational views, partly in cross section, andillustrating digger teeth and mounting means therefore, with anti-coringdevices supported by the digger teeth.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates oneexemplary form of bitmounting means assembly, provided with theanticoring device of the present invention. The bitmounting meansassembly is of the type taught in United States Letters Pat. Nos.3,397,012 and 3,397,013. Briefly, the bit (generally indicated at 1)comprises an elongated shank 2 of circular cross section, terminating atone end in an abutment surface 3 and terminating at the other end in anose portion 4 which may be provided with a hard cutting tip 5. Theshank 2 has, near its abutment end, an annular notch 6.

The mounting means, generally indicated at 7, comprises a body portion 8having a forward surface 9, a rearward surface 10 and a shank receivingperforation 11 extending therebetween. The diameter of the shankreceiving perforation 11 and the diameter of the shank 2 of the bit areso sized that the bit is free to rotate within the shank receivingperforation.

The body portion 8 has a rearward extension 12 terminating in anupstanding anvil portion 13. The anvil portion 13 has an abutmentsurface 14 thereon adapted to cooperate with the bit shank abutmentsurface 3 to determine the gauge of the bit (i.e. the depth to which thebit extends in the shank receiving perforation 11). The mounting meanshas a bottom surface 15 by which it may be welded or otherwise affixedto a driven element of a mining machine.

In use, the bit-mounting means assembly will be driven in a cuttingdirection, generally indicated by the arrow A. It will be readilyunderstood that the forward surface 9 of the mounting means body will besubjected to coring, particularly at the peripheral edges thereof.

FIG. 2 is a perspective view of an exemplary form of anti-coring devicefor use with the mounting means of FIG. 1. The anti-coring device isgenerally indicated at 16 and has a body portion 17 of circularconfiguration. It will be understood by one skilled in the art that theperipheral configuration of the body portion 17 will be determined bythe peripheral shape of the forward surface 9 of the mounting means 7.In the embodiment shown (see also FIG. 3) that portion of the mountingmeans body 8, through which the shank receiving perforation 11 extends,is generally cylindrical in configuration. Thus, in this particularembodiment, the circular body portion 17 of the anti-coring device willhave edge portions substantially conforming to the edge portions of theforward face 9 of the mounting means. This is clearly shown in FIG. 3.

The body portion 17 of the anti-coring device has a central perforation18 adapted to receive the shank 2 of the bit 1 with clearance. Thus, theanti-coring device will not interfere with the rotation of the bit.

The anti-coring device has a tongue 19. The tongue may be provided witha transverse corrugation as at 20.

As is most clearly seen in FIGS. 1 and 3, the forward face of 9 of themounting means 7 may have affixed thereto a U-shaped, strap-like member21. The member 21 forms a slot generally indicated at 22, adapted toreceive the tongue 19 of the anti-coring device. As

will be clear form FIG. 1, the anti-coring device lies along the forwardsurface of the mounting means except at the position of the corrugation20. The corrugation coacts with the strap-like member 21 to assure thatthe tongue fits into the slot 22 with a frictional engagement.

From the above description, it will be apparent that when theanti-coring device 16 is placed in the position shown in FIGS. 1 and 3,it will be held in place by the location of the tongue 19 in the slot22. Thereafter, the bit 1 may be inserted and a retaining ring 23, orthe like, may be affixed thereto at the position of the bit groove 16.In the assembly shown in FIGS. 1 and 3, the bit (extending through thecentral perforation 18 in the anti-coring device will assure that thetongue 19 cannot be inadvertently dislodged from the slot 22.

The bit 1 may be removed from the mounting means 7, for purposes ofreplacement, sinply by disengaging the retaining ring 23 .therefrom andpulling the bit out of the shank receiving perforation 11. Thus, theanticoring device does not interfere in any way with the replacement ofthe bit. Whenever the anti-coring device 16 is to be replaced, it isonly necessary to remove the bit and disengage the anti-coring device.tongue 19 from the slot 22. A new anti-coring device may then bepositioned on the mounting means, whereupon the bit may be replaced.

FIG. 4 illustrates another embodiment of cutter bitmounting means of thetype taught in United States Letters Pat. No. 3,342,532. In thisinstance, the bit comprises a hollow conical member 23 which may beprovided with a hard cutting tip 24. The bit 23 is adapted tofrictionally'engage a nose 25 at the forward end of a bit holder,generally indicated at 26. The bit holder 26 has a shank with a portion27 of larger diameter and an additional portion 28 of smaller diameter.The portions 27 and 28 of the bit holder shank are joined by a taperedportion 29, forming a gaugedetermining abutment surface on the bitholder. The shank portion 28 may be provided with an annular groove 30adapted to cooperate with a retaining means.

The mounting means, generally indicated at 31, comprises a body having aforward surface 32, a rearward surface 33 and a bottom surface 34, bywhich it may be affixed to the driven member of a mining machine. Ashank receiving perforation 35 extends inwardly of the forward surface32. In the preferred embodiment, the shank receiving perforation 35 mayextend all the way through the rear surface 33, to provide an openingthough which fines and foreign material collecting within the shankreceiving perforation may exit therefrom. At the point where the shankreceiving perforation 35 meets the forward surface 32 of the mountingmeans, the perforation is outwardly flared or tapered, to form agauge-determining abutment surface 36 on the mounting means. Theabutment surface 36 cooperates with the abutment surface 29 on the bitholder 26 to determine the depth to which the bit holder extends intothe shank receiving perforation 35.

It will be understood that the shank portion 28 of the bit holder willhave a diameter such that it will be freely rotatable in the shankreceiving perforation 35. For purposes of an exemplary showing, themounting means 31 is illustrated as being provided with a resilientretaining means of the type taught in United States Letters Patent No.2,965,365. In this instance, the mounting means has a transverse hole 37partially intersecting the shank receiving perforation 35. The resilientmounting means is located in the transverse hole and comprises ametallic pin 38 surrounded by a body of resilient material 39 except forthat portion of the pin which extends into the shank receivingperforation 35. The last mentioned portion of the pin 38 cooperates withthe annular notch 30 in the bit holder shank portion 28 to maintain thebit holder in place and to provide a knock-in,'pryout" relationshipbetween the bit holder and the mounting means 31.

The forward surface 32 of the mounting means 31 has affixed thereto aU-shaped, strap-like member 40, which may be identical to the member 21of FIGS. 1 and 3, and which forms a slot 41. The anti-coring device ofthis embodiment is generally indicated at 42. If that portion of thebody of the mounting means 31, containing the shank receivingperforation 35 is rounded, the anti-coring device 42 may be identical tothat shown in FIGS. 1 through 3. If the forward face 32 of the mountingmeans 31 has some other peripheral configuration, it will be understoodthat the anti-coring device 42 will have a matching peripheralconfiguration. Again, the anti-coring device has a perforation 43through which the shank portion 27 of the bit holder extends withclearance. Thus, the anti-coring device 42 will not interfere with therotation of the bit holder 27, nor will it interfere with the removaland insertion of the bit holder in the shank receiving perforation.

The anti-coring device 42 will be provided with a tongue 44,substantially identical to the tongue 19 and having a transversecorrugation 45, similar to the corrugation 20 in the structure of FIG.2. Thus, the tongue 44 will be frictionally engaged in the slot 41 whenthe anti-coring device is in place. Again, since the bit holder 27extends through the perofration 43 in the anti-coring device, it willassure that the tongue 44 will not be inadvertently dislodged from theslot 41. Replacement of the anti-coring device 42 requires only that thebit-bit holder assembly be removed from the shank receiving perforation35. Thereafter, the replacement of the anti-coring device may beaccomplished in a manner identical to that described with respect toFIGS. 1 through 3.

The structure of FIG. 5 is similar to that of FIG. 4, and like partshave been given like index numerals. The bit-bit holder assembly of FIG.5 is identical to that of FIG. 4. The mounting means is also identical,except that the shank receiving perforation 35 is not provided with atapered shoulder or abutment surface 36. In this instance, theperforation 43a, through the anti-coring device 42a, is tapered andserves as the gaugedeterming abutment surface cooperating with theabutment surface 29 on bit holder 27. In all other respects, thestructure of FIG. 5 and its operation is identical to that of FIG. 4.The anti-coring device 4211 does not interfere with either thereplacement of the bit-bit holder assembly or its rotation. Theanti-coring device 42a may be replaced in the same manner described withrespect to the above embodiments.

In all the embodiments thus far described, the bit or bit-bit holderassembly has been of the so-called pick type. There are some embodimentsof pick-type bits which are not intended to be rotatable. It will beunderstood, however that the anti-coring device of the present inventionmay be applied to the mounting means of non-rotating pick-type bits inthe same manner described with respect to the embodiments of FIGS. 1

through 5. If such bits have shanks of non-circular cross section, itwill be understood that both the shank receiving perforation in themounting means and the perforation through the anti-coring device mayhave an appropriate configuration to receive such shanks. In allinstances, the anti-coring device protects the forward face of themounting means from coring.

FIGS. 6 and 7 illustrate the anti-coring device of the present inventionin the form suitable for use with cutter bit-mounting means assembliesof well known type taught, for example, in United States Letters PatentNo. 3,114,537. The mounting means, generally indicated at 46 comprises ametallic block having a shank receiving perforation 47 extendingtherethrough. The shank receiving perforation 47 is of rectangular crosssection. The mounting means may also have a transverse perforation 48for receipt of a resilient retaining means 49. For purposes of anexemplary showing, the retaining means 49 is illustrated as beingidentical to the retaining means shown in FIGS. 4 and 5.

The cutter bit, generally indicated at 50, comprises a head portion 51and a shank portion 52. The shank portion is of rectangular crosssection and is adapted to be received in the shank receiving perforation47. The shank 52 may be provided with a hook-shaped notch 53 adapted tocooperate the metallic rod of the retaining means 49 to hold the cutterbit in seated position.

The head portion 51 of the cutter bit may be provided with a hardcutting tip 51a and gaugedetermining shoulders or abutment surfaces 53and 54, which cooperate with the top surface of the mounting means 46 todetermine the depth to which the shank 52 extends into the shankreceiving perforation 47 In the above mentioned patent various forms ofabutment surfaces or shoulders are taught. For example, only one of theshoulders 53 and 54 may be present, or shoulders extending along thesides of the shank (rather than at the end thereof as illustrated) maybe provided. The nature of the various type of shoulders or abutmentsurfaces on the head portion of the bit does not constitute a limitationon the present invention.

As in the case of the previously described embodiment, the mountingmeans of FIGS. 6 and 7 may have a slot forming means thereon. Forpurposes of an exemplary showing a U-shaped strap 55 is illustrated asbeing affixed to the forward surface 46a of the mounting means. TheU-shaped element 55 may be identical to the element 21 of FIGS. 1 and 3,or the element 40 of FIGS. 4 and 5. It may be an integral part of thelug or affixed thereto by welding or the like. The element 55 forms aslot 56 adapted to receive the tongue 57 of an anti-coring means 58. Thetongue 57 may be identi cal to the tongue 19 of FIG. 2 and may have acorrugation 59 identical to that shown at 20 in FIG. 2. This insures atight frictional engagement between the tongue 57 and the U-shapedelement 55.

As has been discussed above, the configuration of the anit-coring device58 will depend upon the configuration of the mounting means 46. In theembodiment illustrated in FIGS. 6 and 7, the mounting means isessentially block-shaped, having a substantially rectangular forwardface 46a. As a consequence, the anti-coring device 58 is illustrated ashaving a substantially rectangular portion 58a adapted to cover theforward face of the mounting means. While not necessary, the anticoringdevice 58 may have a second portion 58b extending rearwardly of theportion 58a and adapted to lie over a portion at least of the topsurface 46b of the mounting means. The portion 58b has a longitudinallyextending slot 60 located centrally thereof and adapted to accommodatethe head portion 51 of the cutter bit 50. The slot 60 is so sized as topermit the coaction between the abutment shoulders 53 and 54 of thecutter bit head and the top surface 46b of the mounting means. Theportion 58b of the anti-coring device no only provides additionalprotection for the mounting means, but also serves to maintain theanti-coring device in it proper position. This is accomplished throughthe coaction of the cutter bit head portion 51 and the slot 60.

FIG. 8 illustrates a cutter bit-mounting means assembly which issubstantially similar to that of FIGS. 6 and 7, and like parts have beengiven like index numerals. Again a U-shaped slot-forming member isprovided in association with the lug. The anti-coring device is alsosubstantially similar'to that of FIGS. 6 and 7 and again like parts havebeen given like index numerals.

The embodiment of FIG. 8 differs from that of FIGS. 6 and 7 in that theportion 58b of the anti-coring device is provided with a perforation 61rather than a slot of the type shown at in FIGS. 6 and 7. In thisinstance, the shank 52 of the cutter bit extends through the perforation61 and the gauge-determining abutment shoulders 53 and 54 coact with thetop surface of the portion 58b of the anti-coring device 58. Thus, inthis embodiment, the anti-coring device serves not only to preventcoring of the mounting means, but also has an abutment surface for theshoulders 53 and 54. In this way, wear caused by the abutment shoulders53 and 54 will be absorbed by the disposable anti-coring device ratherthan the mounting means itself.

In the embodiment of FIG. 8, it will be understood that dimensionaladjustments will have to be made to accommodate the thickness of theanti-coring device. Thus, the location of the transverse perforation 48in the mounting means will have to be shifted upwardly by a distanceequal to the thickness of an anti-coring device, or the shank 52 of thecutter bit will have to be lengthened by the same distance. Again, thebit 50 serves to cooperate with the U-shaped member 55 to lock theanti-coring device in place.

In both the embodiment of FIG. 6 and 7 and the embodiment of FIG. 8, theanti-coring device does not interfere with removal and replacement ofthe cutter bit 50. In both embodiments, the anti-coring device itselfmay be readily replaced upon removal of the cutter bit.

FIG. 9 illustrates the application of the principle of the presentinvention to bit-mounting means assemblies I of the type taught in theabove mentioned U.S. Pat. No. 3,622,206. Briefly, the mounting means(generally indicated at 62) comprises a block-like structure having ashank receiving perforation 63. The axis of the shank receivingperforation 63 is inclined toward the cutting direction (indicated bythe arrows B). While the angularity of the shank receiving perforationaxis to the cutting direction may be varied, an angularity of less thanis yr ef rrad, s9 thatth somp of force tending to shove the bit into theshank receiving perforation is greater and so that the resultant cuttingstresses on the bit will be more nearly in line with the bit axis.

As illustrated in FIG. 9, the bit (generally indicated at 64) comprisesan elongated shank 65, preferably of circular cross section. The upperend of the shank terminates in a clearance surface 66 lying at an angleto the shank axis and is relieved on opposite sides, one such reliefbeing shown at 6 7. The reliefs form a cutting tip 68 having a cuttingsurface 69 substantially parallel to the axis of the shank 65. The lowerend of the shank terminates in an abutment surface 70 lying at an angleto the shank axis.

The mounting means 62 has a transverse hole 71 extending through themounting means and intersecting the shank receiving perforation 63. Apin 72 is located in the hole 71. The pin 72 carries an abutment surface73 adapted to cooperate with the abutment surface 70 on the bit shank,to determine the gauge of the bit.

A retaining means must be provided to prevent loss of the bit during thecutting operation. For purposes of an exemplary showing, the retainingmeans is illustrated as being a pair of split metal rings 74 and 75captively held in anfannular groove 76 in the mounting means 62. Thesplit metal rings 74 and 75 are so sized as to frictionally engage thebit shank 65.

The mounting means 62 is provided on its forward face 62a with aU-shaped element 77 forming a slot 78. The U-shaped element 77 mayconstitute an integral part of the mounting means 62 or it may be aseparate part affixed thereto by welding or the like. The element 77 maybe substantially identical to the element 21 in FIGS. 1 and 3, theelement 40 in FIGS. 4 and or the element 55 in FIGS. 6-8.

' The anti-coring device is generally indicated at 79. It has a tongue'80 (with a corrugation 81 therein) adapted to be received in the slot78, in the same manner described with respect to the previousembodiments. The anti-coring device 79 has a portion 79a adapted tocover the forward face or surface 62a of the mounting means. Again theconfiguration of the portion 79a will depend upon the configuration ofthe forward surface 620. For purposes of an exemplary show ing, themounting means 62 is illustrated as having a block-like configuration.Thus, the portion 79a of the anti-coring device may be substantiallyidentical to the portion 58a of the anti-coring device 58 (see FIG. 7).

Preferably, the anti-coring device 79 will have a rearwardly extendingportion 79b, similar to the portion 58b of the anti-coring device 58(see FIG. 7). In this instance, the portion 79b extends along a part atleast of the upper surface 62b of the mounting means 62, and has aperforation 82 therein, through which the bit 64 extends. Thus, the bitcooperates with the tongue 80 to maintain the anti-coring device inplace. The anitcoring device does not interfere with removal andreplacement of the bit 64 and may itself be readily replaced uponremoval of the bit 64.

FIG. is similar to FIG. 8 and illustrates a substantially identicalmounting means, cutter bit and retaining means. As a consequence, likeparts have been given like index numerals. The embodiment of FIG. 10illustrates-the use of an anti-coring device (generally indicated at 82)which is similar to that shown at 58 in FIG. 8. The anti-coring device82 has a first portion 82a covering the front surface 46a of themounting means 46, and a second portion 82b covering a large part of thetop surface 46b of the mounting means. The portion 82b has a perforation83 therein, adapted to accept the shank 52 of the cutter bit 50. As inthe case of the embodiment of FIG. 8, the anti-coring device 82 alsoserves as a gauge-determining abutment means, cooperating with theabutment surfaces 53 and 54 of the cutter bit.

Unlike the anti-coring device 58 of FIG. 8, the anitcoring device 82 ofFIG. 10 is not provided with a tongue to be engaged in a slot-formingmeanspln this embodiment, the portion 820 of the anti-coring device hasa hook-like configuration 82c at its bottom edge which is adapted toengage the bottom surface 46c of the mounting means 46. The portion 82aof the anticoring device will have a width at least as great as thatof'the forward face 46a of the mounting means. The hook-like element 820may simply by a continuation of the portion 82a and hence also extendthe full width of the surfaces 46a and 46c. Alternatively, the hook-likeportion 82c may be of a lesser width, simply constituting a centrallylocated extension on the portion 82a of the anti-coring device.

In use, the anti-coring device 82 may be applied to the mounting means46 by first engaging the hook-like portion 820 on the bottom surface 460of the mounting means. Thereafter, the anti-coring device may be pivotedto the position shown in FIG. 10 and the cutter bit 50 may thereafter beinstalled. The combination of the hook-like means 82c and the cutter bit50, passing through the perforation 38, will hold the anti-coring devicein its proper position.

For additional stabilization of the anti-coring device with respect tothe mounting means, it is possible 'to provide the inside surface of theanti-coring device with a lug 84. The lug 84 extends from the insidesurfaces of the portions82a and 82b at the juncture thereof and may belocated centrally of the surfaces. Centrally of the mounting meanssurfaces 46a and 46b, and at the juncture thereof, the mounting meansmay be provided with a slot 85.

The slot is so positioned and so configured as to accept the lug 84. Theinterengagement of the lug 84 in the slot 85 will tend to further impedeany movement of the anti-coring device transversely of the mountingmeans. i

FIG. 11 illustrates a cutter bit, mounting means and retainingmeansidentical to that shown in FIG. 10 and like parts have been given likeindex numerals. An anticoring device is generally indicated at 86. It isin most respects similar to the anti-coring device 82 of FIG. 10.

Thus, the portion 86a, the portion 86b, the perforation 87 and thehook-like configuration 86c correspond to the portions 82a and 82b, theperforation 83 and the hook-like configuration 82c of FIG. 10,respectively.

The anti-coring device 86 can be installed in the same manner describedwith respect to the anti-coring device of FIG. 10, and performs the samefunctions. It differs from the anti-coring device of FIG. 10 in thatrather than a single centrally located lug 84, the embodiment of FIG. 11is provided with a pair of lugs 88 and 89 which are adapted to engagethe side surfaces of-the mounting means 46 at the juncture of theforward surface 46a and top surface 46b. It will be evident to oneskilled in the art that the lugs 88 and 89 will tend to preclude anymovement of the anti-coring device transversely of the mounting means46.

To remove the anti-coring devices of FIGS. Ill and l 1, it is onlynecessary to extract the cutter bit 50. The anti-coring devices may thenbe replaced, followed by the replacement of the cutter bit.

FIG. 12 illustrates the application of the anti-coring device of thepresent invention to the mounting means for a bit or digger tooth of adigging or trenching machine. The digger tooth-mounting means assemblyof FIG. 12 is illustrated as being affixed to an element 90. The element90 may be considered as being the forward portion of the bucket of arotary or chain-type trenching machine. It will be understood that theelement 90 could also be considered as the forward portion of the bucketor shovel of any type of digging machine such as a power shovel, backhoe, or the like. To the forward edge of the shovel element 90 there isaffixed a U-shaped element 91 forming a slot 92. It will be understoodthat the U-shaped element 91 could comprise an integral part of theforward edge of the shovel 90. A mounting means, generally indicated at93, is affixed to the bottom surface of ths shovel member 90. Themounting means comprises a cylindrical element having a forward surface94 and a shank receiving perforation 95. The shank receiving perforation95 has an annular groove 96 therein, in which retaining means 97 and 98are captively held. For purposes of an exemplary showing, the retainingmeans 97 and 98 may be split metal rings identical to those illustratedat 74 and 75 in FIG. 9.

The digger tooth, generally indicated at 99, has a cylindrical shankportion 100 adapted to be received in the shank receiving perforation 95and to be frictionally engaged by the retaining means 97 and 98. Whilethe precise nature of the digger tooth does not constitute limitation onthe present invention, it is, for purposes of exemplary showing,illustrated as being of the double-ended type. Thus, at one end, theshank 100 terminates in a flat surface 101 lying at an angle to the longaxis of the bit and forming a cutting or digging tip 102. The other endof the shank similarly terminates in a flat surface 103 forming acutting or digging top 104. In the position shown, it will be noted thatthe surface 103 cooperates with the bottom surface of the shovel member90 to determine the gauge of the digger tooth. When the cutting tipbecomes worn, the digger tooth may be removed and reversed so that thesurface 101 will abut the bottom surface of the shovel element 90 andthe cutting or digging tip 104 will be exposed.

The anti-coring device is generally indicated at 105. Since the mountingmeans 93 has been described as being cylindrical, the forward face orsurface 94 thereof will be circular. Thus, the anti-coring device 105may be identical to that shown in FIG. 2. Again, it will be understoodthat the anti-coring device 104 may have a different peripheral shape ifthe forward face 94 of the mounting means were to have a configuationother than a circular one.

It will be readily understood that the anti-coring device 105 will notinterfere with removal and reversal or replacement of the digger tooth99. When the digger tooth 99 is in place, it will cooperate with theU-shaped element 91 to maintain the anti-coring device in position. Theanti-coring device may be replaced in the same manner as described withrespect to FIGS. 1 through 3, when the digger tooth 99 has been removed.

FIG. 13 illustrates a modified version of the structure of FIG. 12, andlike parts have been given like index numerals followed by a. Again, theelement 90a may comprise the forward portion of the bucket of atrenching machine, a power shovel, a back hoe, or the like. The primarydifference between the embodiment of FIG. 13 and the embodiment of FIG.12 lies in the fact that the portion 93b of the mounting means 9311 hasbeen extended and the U-shaped element 91a is affixed to, or comprisedan integral part of, the mounting means 93a. The bit 99a and theretaining means 970 and 98a are essentially identical to theircounterparts in the structure of FIG. 12. The anti-coring device a maybe in every way identical to that of FIG. 12. The installation,replacement, operation and characteristics of the anti-coring device1050 are, in every way, identical to those of the anti-coring device 105of FIG. 12.

It will be understood that the nature of the retaining means used in theembodiments of FIGS. 12 and 13 does not constitute a limitation on thepresent invention. The same is true of the cross sectionalconfigurations of the cutter bit shank and shank receiving perforation,except in so far as the perforation in the anticoring device must beproperly configured to receive the bit shank.

FIG. 14 illustrates another application of the teachings of the presentinvention to a bit-mounting means assembly wherein the bit serves as adigger tooth on the lead edge of a scoop, shovel, or like device of anexcavating or earth working machine. In this instance, the bit 106 has ahead portion 107 and a shank portion 108. While the head portion 107 isshown as terminating in a point, the configuration of the head portiondoes not constitute a limitation on the present invention and may bedetermined in part by the type of machine to which it is applied and thenature of the work performed by the machine. The shank 108 is, forpurposes of illustration, shown as being cylindrical. Again, its crosssectional configuration does not constitute a limitation on the presentinvention.

The bit shank 108 is received in a shank receiving perforation 109 inthe mounting means 110. The cross sectional configuration of the shankreceiving perforation 109 is here shown as being cylindrical, but willbe determined by the cross sectional configuration of the bit shank. Theexterior configuration of the mounting means 110, again, does notconstitute a limitation on the present invention and will be dependentupon the nature of the machine device to which it is affixed. Forpurposes of an exemplary showing the mounting means 110 is illustratedas being affixed to the lead edge of a shovel 111. The mounting means110 may be affixed to the shovel in any suitable permanent or removablemanner. The mounting means 110 has a transverse hold 112 adapted toreceive a rod-like element 113. The rod-like element 113 has an abutmentsurface 114 thereon, adapted to cooperate with an abutment surface 115on the bit or tooth 106.

The shank receiving perforation 109 is provided with an annular notch116 containing retaining means 117. The retaining means 117 may again beof any suitable type including one or more split metal rings, or twistedsplit metal ring, a split metal ring of more than one convolution, etc.The retaining means will have a frictional engagement with the shank108.

An anti-coring device is shown at 118, in the form of a ferrule elementhaving a shank receiving perforation 119 similar to the perforation 109and having an annular notch 120. The notch 120 will captively holdretaining means 121 which may be the same as the retaining means 117.The anti-coring device 118 will be inserted on the bit shank and will beshoved into contact with the mounting means 110. It need not be affixedto the mounting means 110 since it can be adequately supported by thebit shank.

Forces acting on the tooth 106 will insure that it will remain fullyseated despite wear of the parts. In many instances, the digger tooth106 may be made of rod stock, rather than an expensive forging operationor the like. Similarly, the bit or tooth mounting means may have asimple shank receiving perforation 109 achieved by drilling rather thanby broaching or the like.

It will be understood that in the embodiment of FIG. 14, a full line orsurface-to-surface contact will be maintained between the bit surface122 and the shank receiving perforation surface 123 whenever there is acomponent of cutting or digging force acting on the bit in a directionranging from a direction which is substantially parallel to the bit axisto a direction which is substantially perpendicular to the bit axis andextending vertically downwardly as viewed in FIG. 14. A typicalcomponent of force within this range is indicated by the arrow A. v 1

FIG. illustrates a structure similar to that of FIG. 14 and like partshave been given like index numerals. In this instance, however, theshank 108a of the bit 106a terminates in an abutment surface 115a whichextends rearwardly and upwardly, as opposed to the abutment surface 115of FIG. 14 which extends rearwardly and downwardly. The mounting means110 is provided with a transverse perforation 112a similar to theperforation 112 of FIG. 14, but positioned slightly differently, asillustrated. A rod-like element 113a is provided, having an abutmentsurface 114a. In this instance the abutment surface 114a is oriented tolie in abutting relationship to 'the bit or digger tooth abutmentsurface 11511.

In all other respects, the structure of FIG. 15 is substantiallyidentical to that of FIG. 14. All of the components act in the sameway.In this instance, however, a full line or surface-to-surface contactwill be maintained between the bit surface 122a and the shank receivingperforation surface 123awhenever there is a component of cutting ordigging force acting on the bit and lying within the range of directionsbetween a direction substantially parallel to the bit axis and adirection substantially perpendicular to the bit axis and orientedvertically upwardly as seen in FIG. 50. A typical component of forcewithin this range is indicated by the arrowB.

It will be understood by one skilled in the art that in either of theembodiments illustrated in FIGS. 14 and 15 the transverse hole 112 or112a could be centrally positioned so that its axis would intersect theaxis of the shank receiving perforation. In addition, it would be withinthe scope of the invention to provide a centrally located transverseperforation and a rod-like element having a pair of abutment surfaces.In this way, the cutter bit or digger tooth could be reversed, dependingupon the type of work done by the digging or earth working machine.

The bits or digger teeth of FIGS. 14 and 15 may be provided with, ashallow depression to receive the retaining means 117. Such a depressionwould increase the retaining ability of the retaining means, but shouldbe shallow so as not to consitute a significant stress raiser. Thedepression should be so configured as to not present a shoulderinterfering with the pry-out feature of the bits. The depression may lieon one side only of the bit or more than one depression may be providedlocated at various positions about the bit. Similarly, the depressionmay be a continuous annular one extending coring. I

fully about the bit. For purposes of an exemplary showing, an annularshallow depression is shown at 124 in dotted lines in FIG. 15. In usingthe term depression it is to be udnerstood that what is meant is aconfiguration which will help to increase the holding power of theretaining means with respect to the bit, but not to a degree to precludethe pry-out feature.

The anti-coring device 118 of FIG. 15 is identical to that of FIG. 14and functions in the same manner. Its exterior configuration will dependupon the configuration of the mounting means 110. The configuration ofthe perforation 119 will depend upon the cross sectional shape of thebit shank 108a. Again, for purposes of an exemplary showing, theanti-coring device 118 is illustrated as a simple cylindrical memberhaving a tapered forward end and a shank receiving perforation ofcircular cross section.

Modification may be made in the invention without departing from thespirit of it. For example, in the above described embodiments theanti-coring device may be removably held in place by suitable means. Itwould be within thev scope of the invention to mount the anti-coringdevice to the forward face of the mounting means by a bolt, a set screwor the like passing through a perforation in the anti-coring device andextending into a threaded hole in the mounting means. Clip means, or thelike, could also be used.

It will be understood by one skilled in the art that, while theanti-coring device has been illustrated as applied to various forms ofbit-mounting means assemblies, its use is not intended to be limited tothose embodirnents shown. The anti-coring device of the presentinvention may be applied to substantially any type of bit-mounting meansassembly, so long as the anticoring device is properly configured toprotect those surfaces of the mounting means which are subject to Theembodiments of the invention in which an exclusive property or privilegeis claims are defined as foling machines, digging machines andearthworking machines, said mounting means having a bit secured therein,said mounting means having at least one forward surface facing thecutting direction and subject to coring, said anti-coring devicecomprises a disposable element adapted to cover a part at least of saidat least one surface of said mounting means and being configured to besupported by said bit and secured thereto in only abutting relationshipwith said at least one surface of said mounting means.

2. The structure claimed in claim 1 including retaining means tomaintain said anti coring device on said bit in said abuttingrelationship with said at least one surface on said mounting means.

3. The structure claimed in claim 1 wherein said mounting means is ofthe type having a perforation therein adapted to receive the shank of abit, said shank receiving perforation forming an opening in said atleast one surface, said anti-coring device having a perforationtherethrough, said perforation in said anticoring device being sopositioned in said anti-coring device as to be coaxial with said shankreceiving perforation when said anti-coring device is in said abuttingposition with said at least one surface of said mounting means, wherebysaid shank of said bit will extend 6. The structure claimed in claim 5wherein said retaining means comprises at least one split metal ringlikestructure.

7. The structure claimed in claim 4 wherein said anticoring devicecomprises a cylindrical member.

8. The structure claimed in claim 7 wherein the forward end of saidanti-coring device facing in said cutting direction is tapered inwardlyand forwardly toward said cutting direction.

1. An anti-coring device for use with a mounting means of the typeaffixed to the driven elements of mining machines, digging machines andearthworking machines, said mounting means having a bit secured therein,said mounting means having at least one forward surface facing thecutting direction and subject to coring, said anti-coring devicecomprises a disposable element adapted to cover a part at least of saidat least one surface of said mounting means and being configured to besupported by said bit and secured thereto in only abutting relationshipwith said at least one surface of said mounting means.
 2. The structureclaimed in claim 1 including retaining means to maintain saidanti-coring device on said bit in said abutting relationship with saidat least one surface on said mounting means.
 3. The structure claimed inclaim 1 wherein said mounting means is of the type having a perforationtherein adapted to receive the shank of a bit, said shank receivingperforation forming an opening in said at least one surface, saidanti-coring device having a perforation therethrough, said perforationin said anti-coring device being so positioned in said anti-coringdevice as to be coaxial with said shank receiving perforation when saidanti-coring device is in said abutting position with said at least onesurface of said mounting means, whereby said shank of said bit willextend through said perforation in said anti-coring device and into saidshank receiving perforation.
 4. The structure claimed in claim 3including retaining means to maintain said anti-coring device on saidbit in said abutting relationship with said at least one surface on saidmounting means.
 5. The structure claimed in claim 4 including an annularnotch in said anti-coring device perforation, said retaining meanscomprising a resilient means mounted in said notch, said resilient meansbeing so sized as to frictionally engage said bit shank.
 6. Thestructure claimed in claim 5 wherein said retaining means comprises atleast one split metal ring-like structure.
 7. The structure claimed inclaim 4 wherein said anti-coring device comprises a cylindrical member.8. The structure claimed in claim 7 wherein the forward end of saidanti-coring device facing in said cutting direction is tapered inwardlyand forwardly toward said cutting direction.